package io.zhengsh.vvip.leetcode.matrix;

import java.util.ArrayList;
import java.util.List;

public class Q54_Spiral_matrix {

    static class Solution {
        public List<Integer> spiralOrder(int[][] matrix) {
            /*
            List<Integer> order = new ArrayList<>();
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
                return order;
            }
            int rows = matrix.length, columns = matrix[0].length;
            int left = 0, right = columns - 1, top = 0, bottom = rows - 1;
            while (left <= right && top <= bottom) {
                for (int column = left; column < right; column++) {
                    order.add(matrix[top][column]);
                }
                for (int row = top + 1; row <= bottom; row++) {
                    order.add(matrix[row][right]);
                }
                if (left < right && top < bottom) {
                    for (int column = right - 1; column > left; column--) {
                        order.add(matrix[bottom][column]);
                    }
                    for (int row = bottom; row > top; row--) {
                        order.add(matrix[row][left]);
                    }
                }
                left++;
                right--;
                top++;
                bottom--;
            }*/
            List<Integer> order = new ArrayList<Integer>();
            if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
                return order;
            }
            int rows = matrix.length, columns = matrix[0].length;
            int left = 0, right = columns - 1, top = 0, bottom = rows - 1;
            while (left <= right && top <= bottom) {
                for (int column = left; column <= right; column++) {
                    order.add(matrix[top][column]);
                }
                for (int row = top + 1; row <= bottom; row++) {
                    order.add(matrix[row][right]);
                }
                if (left < right && top < bottom) {
                    for (int column = right - 1; column > left; column--) {
                        order.add(matrix[bottom][column]);
                    }
                    for (int row = bottom; row > top; row--) {
                        order.add(matrix[row][left]);
                    }
                }
                left++;
                right--;
                top++;
                bottom--;
            }
            return order;

        }
    }
}
